- Netduino Forums
- → Luke Cummings's Content
Luke Cummings's Content
There have been 38 items by Luke Cummings (Search limited from 17-June 23)
#7924 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 19 January 2011 - 06:46 PM in Project Showcase
#8037 I2C Devices using the I2CBus class
Posted by Luke Cummings on 21 January 2011 - 02:09 AM in Project Showcase
I've already touched on this. It can be used by pretty much any I2C device on probably any .NET Micro Framework device.
My work -> A derivative of Pavel Bansky's I2CBus class, but implements the singleton pattern (because it should be implementing the singleton pattern since you are supposed to only have one instance of the I2CDevice class.) You really might want to explore using the singleton pattern so that you guarantee that there is only one instance of the I2CDevice being used by your I2C devices.
I used this in the Bosch BMP085 Digital Pressure and Temperature Sensor
FYI my singleton implementation of the I2CBus class is being used in several projects with as many as four I2C devices on operating on the same bus.
phantom I just finished reworking my quad project to including your I2CBus, works fantastic! I really like this approach, elegant and simple.
Cheers!
#8136 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 23 January 2011 - 03:58 AM in Project Showcase
#8201 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 23 January 2011 - 07:45 PM in Project Showcase
#8231 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 24 January 2011 - 02:05 AM in Project Showcase
#8252 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 24 January 2011 - 06:13 AM in Project Showcase
#8298 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 24 January 2011 - 02:31 PM in Project Showcase
Brandon,
I'm honestly not trying to be pessimistic, I am simply trying to be realistic about the capabilities of NETMF and the hardware at hand. I have a very large amount of experience working with embedded devices and and I also have a very respectable amount of experience implementing, debugging and tuning control loops in autopilot applications.
The thing about quadcopters is that if it fails, it will fail spectacularly, at least resulting in damage to props, probably more. I have actually killed PCBs in quad crashes before due to the intense force involved.
I can certainly understand your enthusiasm in implementing such a system within something that flies, however I may recommend that you practice your EE skills on something that doesn't have the ability to single handedly destroy all hardware involved, not to mention inflict bodily harm (a 12" prop stuck in the wall is not fun...). I'm not saying that you shouldn't do a quadcopter or obey my advice, either, however I would recommend that you seriously consider the limitations of the systems involved.
If you really want to develop autopilot applications in C# .NETMF, I might also recommend that you look into doing it on something like an RC car/boat/hovercraft, etc. All of these are very appropriate for NETMF and I personally have a NETMF powered RC car autopilot project. It's more fun than it sounds and you can always do other stuff like cruise control, etc.
Otherwise, feel free to ignore my advice and proceed. I'm only trying to help
Chris,
I think the point is we alredy are proceeding, I have been flying on .net for the last two days.
#8301 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 24 January 2011 - 03:02 PM in Project Showcase
I would highly writing the control code in native code, and then just calling into it for "command and control" purposes. Basically, the native code does the stabilization and maybe the radio control (so it doesn't go in the wrong direction) but then C# handles the rest.
What is the rest (the part that's not in the control loop)?
Chris
Chris,
You make my point exactly: What is the rest?
If we take the control loop out pretty much nothing and we are looking at Aeroquad ARM. I just wanted to put this out there:
I learned assembly on ARM, I specnt a lot of time in school writing for ARM. Granted I haven't been doing much with that for the last few years, if I truly wanted I could just make Aeroquad ARM version. I think we all need to re-examine our motivation here. For me there is only one reason to program in C#; intellisense. Cheap(free), fast, and good all at the same time(to counter-point my tag line), thats what I want to be able to offer.
I started my quad by working with Aeroquad, then I snapped my arduino in half in a crash. So I decided to try to port to this awesome teensyduino I had laying around. Needless to say that was a chore, after a couple of weeks I gave up. I came up with a new idea, try it on .NET. At the time picked GHI's offering due to the faster processor thinking that would help offset some of the slowness. But that's not the point, the point is I flew one week later. In all my tests so far I have never experienced some sort of instability in .net, granted lots of instability in my control code.
So if you couldn't tell already, my vote is keeping as much as we can in .NET. Drivers are native, drivers are always native. If the firmware is missing something we need (ie reading pulses from the radio), then lets put it in. Edit: (I meant native code in general, possibly Cory's approach) There is only one reason I could write FEZiquad in one week and have it fly, because its .NET.
Anyways I just wanted to get that out there, hopefully we can start off with this goal in mind.
#8398 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 25 January 2011 - 03:53 PM in Project Showcase
#8400 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 25 January 2011 - 05:00 PM in Project Showcase
i thought we were a bit more stable, we still have some work to do then
I add much more success last night, I've had a few hard crashes so I need to spend some time on the hardware.
#8534 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 27 January 2011 - 07:57 AM in Project Showcase
Brandon, you may want to avoid making multiple posts in a row. It makes it very difficult to read the thread.
As for DR&Expo, if you have a computer radio, you can program that in.
I recommend you get a computer radio so you can switch back and forth between multiple DR&Expo settings. I use gentle settings for departure and tighter settings for cruising.
Chris, you may want to avoid being a dbag too many times in a row. It makes it very difficult to read the thread.
#8559 Coding style discussion
Posted by Luke Cummings on 27 January 2011 - 04:07 PM in General Discussion
Move your _coefficients.Length statement to it's own local variable, before you loop and then reference that. It's much faster in netMF than referencing the property.
Also, underscores are against most best practices for .Net
Hey Mark, good catch i didn't even notice I did that. Also the _privateMember or m_privateMember is apart of most c# coding standards I've seen.
#8578 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 27 January 2011 - 07:08 PM in Project Showcase
#8580 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 27 January 2011 - 07:20 PM in Project Showcase
#8642 Coding style discussion
Posted by Luke Cummings on 28 January 2011 - 11:08 PM in General Discussion
Brandon, I think you're reading my comments in the wrong tone - i meant them as a general comment, not targeted at anyone specific. I'm an Aussie, we're pretty layed back and chill - if in doubt, just read my post as a layed back view point
Please feel free to take a look at these links:
IDesign have an exceptional coding standard for C#, which a lot of companies I know of base their standards on. These are basically an expansion of Microsoft's:
http://www.idesign.n...ng Standard.zip - zip with PDF.
This is what Microsoft use internally: http://blogs.msdn.co.../26/361363.aspx
The guideline for creating class libraries is a rather informative read: http://msdn.microsof...y/ms229042.aspx
And this is the book I mentioned (which I recommend every developer - professional, amatuer and enthisuast alike read) - http://www.amazon.com/dp/0321545613/ - on on Book Depository if you're not in the USA (free shipping! woo) http://www.bookdepos...sign-Guidelines
IDesigns C# standards (my personal favourite), section 1 point 4:
Prefix member variables with m_. Use Pascal casing for the rest of a member
variable name following the m_.
public class SomeClass { private int m_Number; }
#9010 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 04 February 2011 - 08:55 PM in Project Showcase
Are there any schematics how to connect the "Dataconcentrator"?
I've taken a deeper look at your framework, it's a good piece of code.
I've added some code to support my peripherals.
I just need an arduino for the Dataconcentrator.
Hey zerov,
I don't have any schematics (it's all just proto'd right now), but at a basic level you will just need to interface your arduino (or any other realtime mcu), and the netmf board over I2C. I used this logic level converter to get them talking: http://www.sparkfun.com/products/8745. It's not actually strictly necessary to use the level converter between the arduino and you netmf board as they are usually 5V tolerant, however since I put the gyro and accel on the same bus you will need the converter(they are 3v only). I will attempt to put together a diagram of how I have everything wired up this weekend.
-Luke
#9028 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 05 February 2011 - 12:56 PM in Project Showcase
I see why you use the Arduino to get the radio data, but why the motors are connected there too? Haven't the Netduino and Domino/Panda native PWM pins? I wanted to use the PWM's on my FEZ.
...
What do you think?
Yeah you noticed that eh? I originally was going to use my arduino as the flight control board. It was just easier to relay motor command over I2C. I actually just finished rewiring the shield so that the pwm pins come from my fez panda directly. So you totally had the right idea there.
So now the razor. Ultimately creating code for interfacing with stuff like the razor is something we want to do, we're just not at that stage yet. Wasting 3ms on parsing the razor's ahrs code is really a waste though, and really from everything i've seen about multicopters so far 50Hz is not gonna be nearly fast enough. You could totally re-write the firmware to get spit out raw data across serial on a demand basis and if you need help i can provide it. My personal recommendation is to just ditch the razor imu for this instead http://www.sparkfun....products/10321.
As far as concetrating all this data on another arduino, I think that adds too much complexity. All I really want the arduino to be is a PPM to I2C converter for the radio. I think eventually I will swap out the teensy for something even smaller.
Cheers
#9060 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 06 February 2011 - 06:36 AM in Project Showcase
But if I take such a 9dof stick, I must make all the calculations on the .netmf device.
The Razor 9dof would do all this calculations:
I have binary messages over serial: [type:length in byte]
[DIYd:4][ID:1][roll:2[pitch:2][yaw:2][checksum:2] => 13byte
But how to request data on demand? just send a byte to the Razor and respond?
Yeah i would just setup a polling loop to check for an incoming message, then provided the data. and honestly you are providing the data so frequently I dont see any value in doing checksum calculations either.
The reason I don't want to be doing calculations on an external board is it reduces accessibility to the code. Principally we want to be able to plug and play hardware, with all control logic being done on the .netmf device. To be honest if your not gonna use the .netmf device to do your control logic then why use it at all. The additional arduino is for convenience, eventually I would like to move to native solution for handling the radio ppm stuff.
#9079 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 06 February 2011 - 07:35 PM in Project Showcase
#9081 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 06 February 2011 - 08:09 PM in Project Showcase
A pull-down resistor on PWM output?
I'm not sure what that would do. The issue is that for the escs to boot they want to see a 0% signal (1000 us pulse, or whatever they have been calibrated for).
#9086 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 06 February 2011 - 09:35 PM in Project Showcase
A pull-down resistor pulls the output to ground - so, there will be 0% PWM output (logic low) during Netduino startup (when the pin is floating high).
Your missing the point, 0% output is not logic low, 0% output is a pulse lasting 1000 microseconds every 20 milliseconds. Holding the pin low would not do anything.
#9089 Quad.Net Quadrocopter for .NETMF
Posted by Luke Cummings on 06 February 2011 - 11:53 PM in Project Showcase
I see - sorry for my misunderstanding.
No problem I didn't mean to be rude in my response. Actually thinking about it though it might be worth a try. I wasn't thinking about the fact that the pins will float during startup, I'm gonna try this anyways it might actually be a solution. Given not what I was thinking of, but I will report back if this works.
Cheers
#9137 BitConverter
Posted by Luke Cummings on 08 February 2011 - 12:31 AM in Project Showcase
When dealing with bit conversions always use the Utility class, for instance working with floats:
public static unsafe float ToFloat(ref byte[] buffer, int offset) { uint value = Utility.ExtractValueFromArray(buffer, offset, 4); return *((float*) &value); } public static unsafe void ToBytes(ref byte[] buffer, int offset, float value) { Utility.InsertValueIntoArray(buffer, offset, 4, *((uint*) &value)); }
Note that the name ToBytes isn't exactly accurate as normally a bit converter would return the array, but usually you are using this to pack data in a long buffer, and using the reference saves the additional hit for making a new array.
or how about a double word sized variable:
public static long ToLong(ref byte[] buffer, int offset) { long value = (long)Utility.ExtractValueFromArray(buffer, offset, 4) << 32; value |= Utility.ExtractValueFromArray(buffer, offset + 4, 4); return value; } public static void ToBytes(ref byte[] buffer, int offset, long value) { Utility.InsertValueIntoArray(buffer, offset, 4, (uint)(value >> 32)); Utility.InsertValueIntoArray(buffer, offset + 4, 4, (uint)value); }
Obviously you could adapt this for any other types you require. These are just what I use in my current project.
Cheers
#9280 Netduino + BL-CTRL 2.0 + I2C = Not working?
Posted by Luke Cummings on 10 February 2011 - 09:11 PM in Netduino 2 (and Netduino 1)
#9598 ATmega 328p programmer
Posted by Luke Cummings on 15 February 2011 - 10:03 PM in General Discussion
Hi guys,
I am looking for a ATmega 328p programmer. The reason is that my 9dof from Sparkfun has (apparently - what a bummer) a flawed bootloaded and needs to be reflashed.
Thus I am wondering if you have any recommendations (possibly being available in EU).
I guess I'll have to solder SPI pins as well. Just great
If you already have a spare arduino you can reflash the arduino bootloader like this:
http://arduino.cc/en...rial/ArduinoISP
- Netduino Forums
- → Luke Cummings's Content
- Privacy Policy